ORIGINAL RESEARCH article

Front. Bioeng. Biotechnol.

Sec. Tissue Engineering and Regenerative Medicine

Volume 13 - 2025 | doi: 10.3389/fbioe.2025.1615953

This article is part of the Research TopicBioengineering and Biotechnology Approaches in Cardiovascular Sciences, Volume IIIView all articles

Connexin 43 Suppression Enhances Contractile Force in Human iPSC-derived Cardiac Tissues

Provisionally accepted
Takuma  TakadaTakuma Takada1Katsuhsia  MatsuuraKatsuhsia Matsuura1*Tatsuro  IidaTatsuro Iida1Toshiharu  KoikeToshiharu Koike1Hidekazu  SekineHidekazu Sekine1Yuhei  HigashiYuhei Higashi1,2Tsukasa  HaraTsukasa Hara1Daisuke  SasakiDaisuke Sasaki1Kyohei  FujitaKyohei Fujita1Yuto  HinataYuto Hinata1,3Junichi  YamaguchiJunichi Yamaguchi1Tatsuya  ShimizuTatsuya Shimizu1
  • 1Tokyo Women's Medical University, Shinjuku, Japan
  • 2Tokaihit Co., Ltd., Shizuoka, Japan
  • 3Ogino Memorial Laboratory, Nihon Kohden Corporation, Shinjuku-ku, Japan

The final, formatted version of the article will be published soon.

Connexin 43 (Cx43) plays a crucial role in maintaining synchronous contraction in the heart. However, it remains unclear whether Cx43 directly influences the contractile force and synchrony of entire cardiac tissues. Previously, we successfully developed human-induced pluripotent stem cell (hiPSC)-derived cardiac tissues capable of directly measuring both the contractile force of the entire tissue and cellular synchrony within it. This study aimed to evaluate whether regulating GJA1, the gene encoding Cx43, could enhance contractility and synchrony in these tissues.Using adeno-associated virus (AAV), we mediated GJA1 overexpression (OE) or knockdown (shGJA1) in bioengineered hiPSC-derived cardiac tissues. Under electrical stimulation at 60 ppm, there were no significant differences in contractile force between the AAV-GJA1-OE and control tissues (0.78 ± 0.39 vs. 0.98 ± 0.43 mN, p = 0.32). Synchrony levels were also similar between these groups (p = 0.20).In contrast, shGJA1 tissues demonstrated significantly higher contractile force compared to scramble controls (1.55 ± 0.38 vs. 1.20 ± 0.15 mN, p = 0.039), although the difference in synchrony was not statistically significant (p = 0.08). RNA sequencing data revealed that a total of 37,199 genes were detected, comparing AAV6-GFP control and GJA1-OE treated hiPSC-CMs, as well as AAV6-shRNA scramble and shGJA1 treated hiPSC-CMs. We highlighted several candidate genes potentially contributing to the enhanced contractile force observed in the shGJA1 group. Furthermore, nineteen common genes were identified between the upregulation of shGJA1 compared to scramble and downregulation of GJA1-OE compared to control, which were associated with cell proliferation, transcription, contraction, and BMP signaling pathways. In conclusion, Cx43-OE did not appear to influence contractility and synchrony, meanwhile, Cx43 suppression may effectively improve contractility without impairing the synchrony in the entire cardiac tissues.Cx43 expression beyond a certain threshold may be sufficient to maintain synchronous contraction in the tissues.

Keywords: Cx43, Connexin 43, hiPSC-CMs, human-induced pluripotent stem cell-derived cardiomyocytes, contractility, synchrony, Bioengineered cardiac tissues

Received: 22 Apr 2025; Accepted: 30 Jun 2025.

Copyright: © 2025 Takada, Matsuura, Iida, Koike, Sekine, Higashi, Hara, Sasaki, Fujita, Hinata, Yamaguchi and Shimizu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Katsuhsia Matsuura, Tokyo Women's Medical University, Shinjuku, Japan

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